Flywheel and screw press for producing ceramic articles

Claim 1

A flywheel and screw press for producing ceramic articles comprising, in combination, a base having an upper surface; a fixed head; support means supporting said fixed head in fixed position upwardly spaced from said upper surface of said base; a movable beam located in the space between said upper surface and said fixed head and being guided on said support means for movement toward and away from said upper surface; mould means carried by said base and provided with cavities open upwardly for receiving a charge of ceramic powder material, punch means carried by said movable beam and designed to cooperate with said cavities for forming ceramic articles, a first pair of hydraulic piston means carried by said base and provided for imparting an upwardly directed thrust to said movable beam; a second pair of hydraulic piston means carried by said fixed head and provided for imparting a downwardly directed thrust to said movable beam, said first and second pair of hydraulic piston means cooperating for controlling the downward stroke of said movable beam for imparting to the powder in the cavities a soft pre-compression causing a first thickness reduction of the powder mass and an appreciable expulsion of the air enclosed; a third pair of hydraulic piston means carried by said fixed head and controlled for acting on the movable beam and performing the first compacting step after the soft pre-compression; a fourth pair of elastically compressible hydraulic piston means carried by said base and provided with adjustable rod ends and able to interfere with said movable beam when the latter is further lowered during said first compacting step for impressing to said movable beam an upwardly directed thrust helping the elastic return of the compacted powder mass to raise said movable beam immediately after said first compacting step, allowing the expulsion of the remaining air; a flywheel disposed above said fixed head, a screw threadedly engaged to said flywheel and carried by said fixed head; motor means provided for alternatively imparting to said flywheel and screw rotation in one and in the other direction for lowering and raising said flywheel and screw, and control means for controlling said motor means to operate said flywheel and screw in the lowering direction in due time for impacting said movable beam and performing a strong second and ultimate compacting step of the powder material immediately after the elastic return of the powder material; and hydraulic circuit means for timely controlling and energizing all the pairs of said hydraulic piston means, said hydraulic circuit means, interconnecting all the pairs of said hydraulic piston means.